Maintaining proper counts of inventories of goods, such as retail goods or raw materials, is important to many different businesses. For example, a retail store such as a supermarket must take pains to ensure that shelves are fully stocked, and yet consumer interaction with the products on the shelves can make this difficult. Customers may, for example, place items in the wrong location or oriented the wrong way for effective sales. Typically inventory status is determined by a human, for example, walking through the aisles and counting stock. Recent efforts to automate this process have included tagging (e.g., using Radio Frequency identification (RFID)) of products, scale sensors in shelves, and so forth. All of these automations, however, still suffer from some of the basic problems that occur in real-world use of products. A scale, for example, does not aid in detecting inventory levels if an item is placed on the wrong shelf, and it does not help with proper orientation if the item is improperly oriented.